There exist several technologies that can produce electricity on a premises, whether a residential or commercial building. Among these are photovoltaic panels (e.g., solar panels), small scale natural gas turbines (also known as micro-turbines), small-scale wind turbines (in contrast to the large turbines used in grid connected wind farms), low pressure water turbines, high-pressure low flow water turbines, and fuel cells using hydrogen, natural gas, and potentially other hydrocarbons. These technologies are herein referred to as “distributed energy sources.” Distributed energy sources have been deployed only to a very limited extent for reasons of cost, convenience, and a lack of harmonized grid inter-connection standards. Historically, power storage and supply devices typically involve the charging of batteries that store energy in the event of a power failure of a home or business' main source of electricity, which is normally provided from a utility power grid connected to the home or business and are designed to support the entire or selected electrical load of the home or business. As a result, residential and commercial power storage and supply devices are typically very large and cumbersome. Some power storage and supply devices use alternative energy sources, such as the ones listed above. The power storage and supply devices store the electric power produced by an alternative energy source and may even supply power to a utility power grid, in essence operating as a small, distributed power generation plant. Many local, state, and federal government agencies, as well as private utility companies, are encouraging this practice as evidenced by the changing regulatory environment and passage of such distributed power and energy storage policies as AB970, SB412, SB 14 and AB44. Further, rule makers such as FERC, CASIO, and the CPUC are making priority changes (e.g., CEC Integrated Energy Policy Report, CAISO implementation of FERC Order 719, etc.), which encourage or mandate the use of distributed energy storage and power generation. Unfortunately, the use of alternative energy sources in conjunction with such power storage and supply device systems has been limited primarily because of cost and convenience and communications standards.
In recent years, however, the costs associated with adopting and using alternative energy sources has decreased substantially as distributed energy power and storage technologies have been refined, sales have increased due to the creation of new markets (e.g., plug-in electric hybrid vehicles and the globalized adoption of solar technologies), and more suppliers have entered the market resulting in greater manufacturing capacity and market competitiveness for both photovoltaic and battery manufacturers. The cost barriers to distributed electrical technologies are also eroding due to factors such as real and/or perceived increases in the cost of electricity and other forms of energy, the widespread adoption of time-of-use pricing (TOU) or real-time pricing (RTP) by utilities, favorable terms for the utilities' purchase of power from such distributed sources, and government financial incentives (e.g., The federal business energy investment tax credit available under 26 USC §48 was expanded significantly by the Energy Improvement and Extension Act of 2008 (H.R. 1424), enacted in October 2008, etc.) which encourage investment in distributed and environmentally more benign electrical technologies.
Adoption of distributed energy power and storage technologies is also increasing due to the widespread implementation of an Advanced Metering Infrastructure; commonly referred to as AMI. Advanced metering systems are comprised of state-of-the-art electron/digital hardware and software, which combine interval data measurement with continuously available remote communications. These systems enable measurement of detailed, time-based information and frequent collection and transmittal of such information to various parties. AMI typically refers to the full measurement and collection system that includes meters at the customer site, communication networks between the customer and a service provider, such as an electric, gas, or water utility, and data reception and management systems that make the information available to the service provider. With AMI utilities are now better able to manage installed devices within the homes of participating consumers that, under utility control, selectively disable energy-consuming devices (e.g., hot water heaters or air conditioning units) in response to peak loading conditions. Furthermore, utilities are now able in certain cases to remotely activate and aggregate distributed power and energy supplies to increase the supply of electricity to constrained parts of the electricity grid.
There has been an increasing emphasis in recent years on energy conservation. Electric utilities have also come under increasing pressure to reduce the need to fire up polluting power plants to serve peak demands, such as during hot summer days. With the enactment of current legislation and rulemaking (e.g., AB970, AB32, and FERC Order 719, etc.), electric utilities also have an incentive to “smooth out” energy demand to minimize the need to install new power transmission and distribution lines; further negating environmental and land use issues. Examples of a few of the ways in which utilities can perform these tasks are referred to as “demand side management” and “supply side management.” Demand side management refers to the selective reduction of energy demand in response to peak loading conditions. For example, utilities have for years installed devices in the homes of participating consumers that, under utility control, selectively disable energy-consuming devices (e.g., hot water heaters or air conditioning units) in response to peak loading conditions. As another example, utilities are able in certain cases to remotely activate energy supplies to increase the supply of electricity to parts of the electricity grid. It would be advantageous to provide more sophisticated control mechanisms to permit electric utilities and others to effectively monitor and control distributed energy resources, such as storage units capable of storing electricity and reselling it to the grid on command. It would also be advantageous to provide more sophisticated demand side management tasks using aggregated resources to manage localized constraints on the utility grid (e.g., substation, feeder-line, residence, etc.).